MOSUL, Iraq — Last summer, two dozen U.S. Army Rangers headed for the Iraq-Syria border to figure out how foreign fighters were slipping through western Iraq’s barren deserts.

As they had done in the past, the Rangers took positions around each village and Bedouin encampment. At one village, an officer named David, accompanied by a small security team, strode into the center looking for someone who would talk. Unlike the clean-shaven, camouflage-clad Rangers, David wore a thick goatee and civilian clothes. The Rangers carried long, black M-4 carbine rifles. David walked with a small 9mm pistol strapped to his leg. The Rangers spoke English. He spoke Arabic tinged with a Yemeni accent.

As he recounts the day, David met a woman with facial tattoos that marked her as her husband’s property. As they chatted, the pale- skinned, sandy-haired North Carolina native imitated her dry, throaty way of speaking. “You are Bedu, too,” she exclaimed with delight, he recalls.

From her and the other Bedouins, the 37-year-old officer learned that most of the cross-border smuggling was carried out by Shamar tribesmen who peddle cigarettes, sheep and gasoline. Radical Islamists were using the same routes to move people, guns and money. Many of the paths were marked with small piles of bleached rocks that were identical to those David had seen a year earlier while serving in Yemen.

David is part of a small cadre of cultural experts in the Army known as foreign-area officers. The military would only allow him to be interviewed on the grounds that his last name and rank be withheld. U.S. officials say he’ll be spending the rest of his career in the Middle East, often operating alone in potentially hostile territory. Naming him, they say, would make him more vulnerable to attack.

His colleagues in Iraq say his presence has been invaluable. “We ought to have one of these guys assigned to every [regional] commander in Iraq,” says Col. John Bayer, chief of staff for Maj. Gen. David Rodriguez, the commander of U.S. forces in the northern third of the country. “I’d love to say ‘assign me 100 of these guys.’ “

That’s not happening. Instead, the military is pulling David out of Iraq later this month along with seven other officers who make up his unit. Before the end of the year, David will resume his previous post in Yemen.

The decision to disband the Iraq unit is part of a continuing debate within the Pentagon about how best to fight unconventional wars that don’t lend themselves to the Army’s traditional reliance on firepower and technology. The issue: How should the Army use officers who specialize in accumulating historical, political and cultural knowledge.

Earlier this fall, the U.S. embassy and the military’s main headquarters in Baghdad concluded that the work of David and his colleagues was duplicating the efforts of other personnel. David’s team is part of the Pentagon’s Defense Intelligence Agency. It was sent to Iraq to advise U.S. military and State Department officials.

“While it’s regrettable to lose experienced people, overall there are many more Arabic speakers working for us [in Iraq] than you might think,” says one U.S. embassy official in Mosul.

To some in the Defense Department, the foreign-area teams offer a model for how all types of future officers should be trained. A report approved by then-Deputy Defense Secretary Paul Wolfowitz in January, specifically ordered the military to beef up its linguistic and cultural capabilities.

“Language skill and regional expertise have not been regarded as warfighting skills and are not sufficiently incorporated” into war plans, the report concluded.

In Iraq, cultural misunderstandings have contributed to mistakes. The decision to disband the Iraqi Army, which the U.S. saw as a tool of Saddam Hussein and a symbol of oppressions, created ill-will among Iraqi soldiers, who saw it as a source of national pride and pensions. As they battled an insurgency, U.S. commanders also struggled to understand Iraq’s deep tribal and sectarian divisions. American officers working with Iraq’s fledgling security forces frequently complain that police officers and soldiers sometimes put tribal allegiances ahead of their duty as officers.

Col. John D’Agostino, who oversees David and his colleagues and has also been recalled, says he disagrees with the decision to close the Iraq foreign-area officer unit. He says these officers are often overlooked, for which he blames “a Cold War mindset in which we are still fighting the hordes in Eastern Europe.” When David leaves, the U.S. embassy’s regional office in Mosul won’t have a single Arabic speaker or Middle East expert on its staff.

In total, there are currently about 1,000 foreign-area officers in the Army. Currently, 145 of them specialize in the Middle East, the fourth-largest number devoted to a single region. The biggest concentration is in Europe. Typically, they spend big chunks of their careers working as the military’s eyes and ears in remote and dangerous outposts. They coordinate military exercises and gather intelligence about the forces in their region. “They operate at the ends of the earth,” says retired Col. Jack Dees, a longtime foreign area officer. “Often they are the one military guy out there representing their nation.”

David decided he wanted to be a foreign-area officer even before he graduated from the United States Military Academy at West Point because he wanted to live overseas. He grew up in rural North Carolina, shuttling between an orphanage and several foster homes after he was taken away from his parents by the state. He chose West Point because it was free. “I was also looking for a sense of family and belonging . . . you know, all that psycho-babble stuff,” David says today.

After commissioning as an officer, he flew Apache attack helicopters for a decade, in Iraq and along the border between North and South Korea. He then spent six months in Bosnia as the American liaison officer on a French division staff. In 1999, as soon as he was eligible, David applied to become a foreign-area officer.

The military dispatched him to Morocco where he spent part of his time coordinating U.S.-Moroccan military exercises. His main job was to travel the region and learn about its culture and people.

On returning to the U.S. in 2001, David spent 18 months learning Arabic at the Defense Language Institute in Monterey, Calif. He then earned a master’s degree in Arabic studies from Georgetown University, focusing on the co-existence of Yemen’s tribal culture with its fledgling democratic institutions.

In preparation for a position at the U.S. embassy in Yemen, he learned all he could about qat, a narcotic leaf that’s chewed in the region. He says he’s never actually chewed it — an act that would get him bounced from the Army — but he quickly developed an ability to talk about it.

“The three books you have to read are: ‘The Flowers of Paradise: The Institutional Uses of Qat in North Yemen’; ‘Qat in Yemen: Consumption and Social Change’; and ‘Eating the Flower of Paradise: One Man’s Journey Through Ethiopia and Yemen,’ ” he says.

This knowledge allowed him to initiate conversations when nothing else worked. By the end of his two-year tour in the country, he could talk fervently about qat’s cultivation, its aphrodisiac qualities and its price fluctuations.

David’s mission was to keep senior U.S. military officials abreast of what was going on in Yemen, Osama bin Laden’s ancestral home, specifically within its military. He traveled extensively, building a network of contacts with tribal leaders who would ensure safe passage through their areas. He became legendary for hosting elite receptions at his home in the capital Sana where he gathered gossip and information. Yemenis worth talking to won’t set foot in the U.S. embassy for fear of being labeled imperialist lackeys. David’s house had a lower profile.

When Gen. John Abizaid, the top U.S. commander in the Middle East, visited Yemen in January 2004, David set up a dinner with its political elites as well as military attaches from Saudi Arabia, Egypt and Jordan. They discussed elections in Iraq and smoked cigars on David’s back porch. Gen. Abizaid’s staff confirms the event took place.

David’s biggest coup was convincing Sana’s most-important sheik to attend one of his receptions. “He brought his wife and daughter, which was huge because they never take their women anywhere,” David says. The sheik, Abdullah Mohammed Abdullah Al-Thor, says in an interview he attended several events at David’s house and that the officer is a “very, very good friend.”

In May, after two years in Yemen, David was dispatched to Mosul. His role was to help senior commanders build relationships with Iraqis the U.S. would be able to trust in advance of any reduction in the U.S. military presence. “If things are going bad, it is my responsibility to know who we should call,” he says.

In Iraq, he prepped Gen. Rodriguez, the chief of staff for northern Iraq, for meetings with senior Iraqi leaders. He also gave State Department employees extensive tutorials. The current State Department staffers in the Mosul office, who cover most of northern Iraq, are South America and Asia experts. A key lesson involved the proper etiquette of arguing with Arabs. David goaded the diplomats to be less diplomatic. When Arabs yelled, David told them to yell back.

One recent day, David sat down with a Foreign Service civilian who had arrived from Santiago, Chile. He started by explaining how one became a sheik and that not all sheiks are equal. He briefed him on the major ethnic groups and political parties in the region.

After two hours the State Department official seemed lost. “How do you keep all this stuff straight in your head?” he asked.

David discovered that many of the U.S. interpreters, including that of Gen. Rodriguez, spoke poor Arabic because the people doing the hiring didn’t speak the language. “When Gen. Rodriguez spoke he was articulate. His interpreter made him sound like an eighth grader,” David says.

The general’s interpreter was re-assigned and David began screening new hires. A few weeks later, he figured out that one interpreter — who had access to intelligence about U.S. operations — had lied about his background. The tip-off: The interpreter said he was from Suleimaniya in northern Iraq. Based on the Kurdish dialect he spoke, David could tell he was from a village outside Mosul. “We don’t know his agenda; we just know he was deceitful,” says an intelligence officer who works with David. The interpreter was fired.

David made his biggest impact supporting the 8,000 U.S. and Iraqi troops who assaulted Tal Afar, a city in northwestern Iraq that had become a major insurgent haven. In 2004, the U.S. tried to drive insurgents from the city. The operation was a disaster. Two days into the assault, Turkey, which has historic ties to the Sunnis in the city, complained publicly to U.S. authorities in Ankara and Washington that the attack was too heavy-handed. Turkey threatened to close a border crossing with Iraq through which more than 30% of Iraq’s gasoline moves. The U.S. abruptly halted the attack after two days.

Before a renewed attack this September, David, working with officials at the U.S. embassy in Ankara, hatched a plan to placate the Turks. Each night, after traveling through the area, he emailed photos with a time, date and GPS stamp to the U.S. embassy in Ankara. He also sent along the U.S. military’s major-incident reports. That allowed the embassy to give Turkish military officials meticulous daily briefings.

Turkey’s foreign minister complained about the attack in a meeting with Secretary of State Condoleezza Rice, but didn’t ask the U.S. to call it off, says a U.S. official in Ankara.

David’s biggest contribution in Tal Afar drew on virtually all of the skills he had amassed in five years as a foreign-area officer and a close friendship he’d forged with the city’s mayor.

Three months before the attack on Tal Afar, U.S. and Iraq officials had installed Najem Abdullah, a senior official from nearby Mosul, to run the city. During his brief tenure, the Sunni mayor earned the grudging support of Tal Afar’s warring Sunnis and Shiites. Without him, U.S. commanders feared Tal Afar would slip into all-out war.

David and Mayor Najem had become close in the weeks leading up to the invasion. David teased him about his purple-tinted, rhinestone- encrusted sunglasses. He stood with him in tougher times as well. When Shiite sheiks, through their allies in the police, physically blocked key Sunni sheiks from attending a meeting, David stormed out, earning the mayor’s respect.

“I consider David like an Iraqi in the city,” Mayor Najem says today. “When he discusses things with the tribal leaders he does it like an Iraqi. He raises his voice. He is passionate just like the Iraqis.”

In early September, as U.S. and Iraqi forces readied their second assault on Tal Afar, the mayor began to doubt whether he could continue in the job. The pressure of running the divided city had become unbearable. Death threats from Sunni extremists forced the mayor’s family to flee their home. The Sunni mayor worried that Tal Afar’s Shiite-led police would use the invasion to settle scores with Sunnis.

Midway through rancorous meetings in the mayor’s office, the two men stepped out into a dimly lit side room. “Why should I stay here? What is the point?” Mayor Najem recalls asking David.

In this moment of doubt, David and the 49-year-old Iraqi held hands — a common sign of affection among Arab men. David promised to move the mayor’s wife and children to a new city. (They’re currently in hiding.) He also pledged to make sure that U.S. commanders acted on the mayor’s concerns about the city’s Shiite security forces.

“David talked to me as a friend and a brother and convinced me to stay,” the mayor says. “He is like Lawrence of Arabia.”